Ridge Gap Waveguide Monopulse Comparator for Millimeter Wave Direction Finding Systems

This paper introduces a comparator network for monopulse radars at the millimeter wave Ka band (26-29GHz). The network design is based on four Magic T’s connected in an assembly through various bend junctions and lines. The network is implemented using gap waveguide technology where each Magic T consists of a hybrid coupler loaded with a 90° phase shifter at the output ports. The full comparator network achieves 15 dB isolation between the output ports. Less than 10° phase imbalance is achieved with 11% bandwidth. Compared time domain and frequency domain simulations show very good agreement in these results which validates the network performance.